Overview

The first Debriefing will cover the following topics:

1. Unix

2. Packaging

3. Object-Oriented Programming

The Debriefing will consist of definitions, short answers, code evaluation, debugging, and programming questions related to the Project 01.

For the programming section, you will be able to use your computer (but only after you have completed all the other sections).

Below are examples of the type of questions that may be asked on the Debriefing. It is mean to be representative, rather than exhaustive (ie. there may be questions that show up on that are not show below).

Definitions

Briefly define the following terms:

1. Unix

2. Shell

3. Script

4. She-bang

5. Module

6. Package

7. Class

8. Instance

9. Field

10. Method

Short Answers

1. Identify which Unix commands you would use to perform the following tasks:

   a. Check to see what files are in the current directory.

   b. Find out where you are in the filesystem.

   c. Move into another directory.

   d. View the contents of a file.

2. What exactly is git? What does it allow us to do? Explain the commands you would use to save the changes you have made to a project and send them to Bitbucket.

3. Explain how a single file be both a script and a module. In particular, describe how a file can distinguish between being executed as a script and being loaded as a module.

4. Describe how you would make a script executable and how a script could access command line arguments passed to it?

Code Evaluation

1. What is the result of the each of the following lines of Python code:

   color0 = Color()            # 1
   color1 = Color(1, 2, 3)
   
   print color0                # 2
   print color1
   
   print color0 == color1      # 3
   

   Additionally, for each of the markers (ie. # 1, # 2, # 3) identify which protocol method is being called and what happens inside each one.

2. What is the result of the each of the following lines of Python code:

   point0 = Point()
   point1 = Point(y=3, x=4)
   point2 = Point(point0.x + point1.x, point0.y + point1.y)
   
   print point0
   print point1
   print point2
   

3. What is the result of the each of the following lines of Python code:

   image = Image()
   print image
   print image[Point(image.width, 0)]
   
   image.width = 100
   print image
   print image[Point(image.width, 0)]
   

4. What is the result of the each of the following lines of Python code:

   image = Image()
   point = Point(0, 0)
   color = Color(1, 2, 3)
   
   print image[point].r, image[point].g, image[point].b
   
   image[point] = color
   print image[point].r, image[point].g, image[point].b
   
   image[point] = Color(color.b, color.g, color.r)
   print image[point].r, image[point].g, image[point].b
   
   image[point] = Color(g=color.g)
   print image[point].r, image[point].g, image[point].b
   

Debugging

1. Identify and fix the following implementation of the Color class:

   class Color(object):
       def __init__(self, r, g, b):
           r = int(r)
           g = int(g)
           b = int(b)
   
       def __eq__(self, other):
           if self == other:
               return True
   
       def __str__(self):
           print 'Color(r={},g={},b={})'.format(Color.r, Color.g, Color.b)
   

Programming

1. Add a new draw_square method to the Image class:

   def draw_square(self, point, length, color):
       ''' Draw a square given the upper left corner point and the
       length of each side with the given color '''
   

2. Add a new draw_rectangle_frame method to the Image class:

   def draw_rectangle_frame(self, point0, point1, length, color):
       ''' Draw a rectangular frame from point0 to point1 with a border
       of size length and with the given color '''
   

3. Add a new draw_wave method to the Image class:

   def draw_sinewave(self, point0, point1, amplitude, color):
       ''' Draw a sinewave from point0 to point1 with the given
       amplitude and color '''
   

4. Write a script draw_circles.py that takes in three arguments:

   $ ./draw_circles.py MIN_RADIUS MAX_RADIUS NCIRCLES
   

   This script should draw NCIRCLES circles with radii between MIN_RADIUS and MAX_RADIUS and emit the PPM image.

5. Write a script draw_house.py that takes in three arguments:

   $ ./draw_house.py HOUSE_COLOR DOOR_COLOR WINDOW_COLOR
   

   This script draws a house with HOUSE_COLOR that has one door with DOOR_COLOR and two windows with WINDOW_COLOR.